青い鬼と赤い鬼 green and red Oni
A green Oni and a red Oni fought about their territory and begun to throw stones at each other. The clever Red Oni won the battle.
The green Oni said: "If you put on a 蓑笠 straw coat and clean the well, I will make it rain!" and jumped right into the sky above the clouds. The 天の神様 Kami in heaven thought this was kind of funny and made more Oni in various colors.

akai hi 赤い火 red flames
If someone passed the graveyard after sunset, there were red flames hopping around to be seen.
Two or three blue Oni spit fire and ate it again, amusing themselves with the red flames.
When a brave samurai went there to check out the real reason, there were some beggars sitting on the ground, sticking burning leaves of local potatoes in their nose and blow them out.

oni ningyoo 鬼人形 demon dolls
A craftsman with special skills made a carving of 酒顛童子 Shuten Doji for the festival float, with a red and blue demon at its side.
But the wandering souls of a young couple that had committed suicide in dispair begun to stick to the float.
鬼人形 demon dolls of the two were made and hung outside to make their spirits go away.

. the Demons Zenki 前鬼 and Goki 後鬼 .
the husband Zenki 前鬼 and his wife Goki 後鬼, servants of En-no-Gyôja 役行者 En no Gyoja.
They take part in oni no gyooretsu 鬼の行列 a Demon parade during the festival in honor of En no Gyoja.
Apart from Zenki and Goki, many red and blue demons march along on August 3rd.

大笹生の黒鬼伝説 Black Oni legend from Ozaso
In the North-West of Fukushima city there is a mountain plateau called Ozaso.
Once upon a long long LONG time, there lived a black Oni.
He often came down from his mountain to eat villagers and travelers and cause a lot of trouble as 人食い鬼 a man-eating Oni.
Even the priest from a local temple was eventually eaten by the Oni.
Then one day a traveling monk came to stay in the village and heard the story. The villagers asked him to drive out the Oni, but first he refused, because he had no trust in his power to do so.
The villagers talked to him again and made him hold a memorial service for all the perished souls.
As things go, the monk stayed at the temple and became its priest after all.

One night as he slept, Dainichi Nyorai appeared at his pillow and taught him how to get rid of the man-eating Oni:

Haragosha Shrine shrine was built in the new village of the people of the Kurokami Area after they resettled following a large eruption in the Edo Period (the Annei Eruption).
The god from the shrine of their old home is enshrined here.
... This three meter-high stone torii has been buried in volcanic lava and ash since the eruption of Sakurajima in 1914, leaving just its head peeking out. It was actually completely covered but builders discovered it while doing excavation work in the process of building a school in the area. The village mayor took the decision to leave it partially buried in remembrance of the devastating eruption. - reference -

At the temple 廬山寺 Rozan-Ji in Kyoto, there are Oni of three colors.
The red Oni symbolizes greed, the green Oni anger and the black Oni stupidity.
They are the three most important bonnoo 煩悩 earthly desires